Still Tuning....For a better GPP

[SJP51]

Shot my first trad kills a few weeks ago. Neither arrow was a pass through, but did poke out both sides. Seems pass throughs are more desireable: Better blood trail, indication of more available energy if bone is hit, etc.

I've gotten better at blade shapening with new technique. That should really help pass throughs.

At my draw length, I'm was shooting a 49# recurve with an arrow of only 446 gr for 9.0 GPP, and 13.5% FOC. I'd like to get the GPP up so the arrow has more momentum to help achieve pass through, so I swapped inserts: Removed 19 gr insert and used a 50 gr brass insert. Now the arrow is 477 gr, 9.6 GPP, and 15.8% FOC.

Went to shoot from 20 yards using 1-each 477 gr and 4-each 446 gr arrows. Made sure I did NTO see the insert so I't be a truer test. Here's what I saw:

- I did NOT see a lot of kick-out of the heavy arrow being under spined. I account that to the feathers. Bare shaft tuning will likley indicate a shorter length is warranted.
- I did NOT percieve the bow to any quieter from shooting the heavier arrow.
- I did NOT perceive the arrow to actually be any slower. But it should be. Likely just not enough difference to see.
- I DID see vertical shot consistency through multple 5-shot ends. Sometime the heavy arrow was a tad high, sometimes a tad lower. But the group was all mixed into a 8" circle.

I'm curiuos if the added GPP to gain an incremental increase in Momentum is worth it and will it actually help with pass throughs.

[Dkincaid]

What kind of broadhead are using


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[NCTx Dude]

Not a trad guy but did change to a heavier arrow & added FOC this season and was impressed with the penetration results. Tested on pigs of various sizes

[SJP51]

What kind of broadhead are using


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125 gr VPA 3-blade.

[SJP51]

Duplicate post.

[Briar Friar]

IMO poking out both sides is a pass thru...just not complete pass thru. The broadhead passed through the whole cavity.

My current arrows are 640 gns with 100 gn insert and 300 gn heads. My FOC is “Stupid”. I feel confident that my arrows didnt passthru a spike I shot/killed due to “over”spin and the 3 blade VPAs. This one of the few times I actually considered the benefit of Kinetic Energy in that all that energy was dumped into the offside shoulder and vitals and 3 blades shredded the organs along the way. I think with a 2 blade single bevel there mightve been more penetration but still alot of lateral energy dump due to shaft spin.

As you meander down your path...consider the spin of your arrows and the friction from the surface area of your broadhead.

Dead critters dont know if theyve been passed thru or not.

Good luck Mr51

[DRT]

Yup
Two holes is what you're getting. The swap of inserts is only a net gain of 32 grains. Not going to make an incredible difference in bow noise or arrow speed.

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[Briar Friar]

At 58# @28 that still puts me only at 11 gpp

I likely draw in actuality around 54 lbs and that still puts me at around only 11.85 gpp.

[SJP51]

IMO poking out both sides is a pass thru...just not complete pass thru. The broadhead passed through the whole cavity.

My current arrows are 640 gns with 100 gn insert and 300 gn heads. My FOC is “Stupid”. I feel confident that my arrows didnt passthru a spike I shot/killed due to “over”spin and the 3 blade VPAs. This one of the few times I actually considered the benefit of Kinetic Energy in that all that energy was dumped into the offside shoulder and vitals and 3 blades shredded the organs along the way. I think with a 2 blade single bevel there mightve been more penetration but still alot of lateral energy dump due to shaft spin.

As you meander down your path...consider the spin of your arrows and the friction from the surface area of your broadhead.

Dead critters dont know if theyve been passed thru or not.

Good luck Mr51

I stand corrected: Not a "COMPLETE" pass through.

The VPA's did a lot of damage. Heck of a set of holes. I was surprised she ran off 125 yards. Lucky I found her. Complete pass through might not have made that much difference as I got one lung but angled behind the other. Just trying to optimize my set up.

Thanks for the sage advise.

[Trumpkin]

A sample size of two dead animals is not enough to make a real judgement. You also don't mention what bow you're shooting. The only important measure of performance is arrow speed at a given arrow weight (assuming you have a well tuned setup). Adding the ~30 grains of weight will make some difference. It's questionable whether you will be able to identify that difference, but IMO arrow penetration is a cumulative game. Sharper broadheads, a few FPS difference due to a faster bow or a cleaner release, a little extra weight at a given speed, broadhead design, etc. will add up to helping an arrow pass through more effectively. That said, you probably need to shoot another 15-20 animals with your existing setup to know if it's really not effective enough for your liking. As others have said, two holes is all you need!

[DRT]

I'm not a person who buys into the super FOC either. A well tuned arrow 9.5 to 11 gpp with 15 to 20% foc is gonna give you two holes in most north American big game.

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[SJP51]

You're right. But 2 kills is all I've got to work with.

The bow is 49# at my draw and chronos 191 fps at 5 ft shooting a 446 gr arrow. It certainly poked 2 holes.

I need to re-tune with the heavier inserts and see what's what. With sharper blades, a tad more ME/KE, a tad more FOC, and hopefully things will come together a tad better.

[SJP51]

I'm not a person who buys into the super FOC either. A well tuned arrow 9.5 to 11 gpp with 15 to 20% foc is gonna give you two holes in most north American big game.

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I'm admitted rookie. But that kind of agrees with my thinking. I set up for 19% FOC and went point down too much for my taste.

[Trumpkin]

You're right. But 2 kills is all I've got to work with.

The bow is 49# at my draw and chronos 191 fps at 5 ft shooting a 446 gr arrow. It certainly poked 2 holes.

I need to re-tune with the heavier inserts and see what's what. With sharper blades, a tad more ME/KE, a tad more FOC, and hopefully things will come together a tad better.

That's great speed for that arrow weight! I'd have a hard time giving up that trajectory if it were me. You might consider switching broadheads to something like a 2 blade with bleeders, assuming you're using the VPA 3 blades. If it's the two blades, disregard everything I just said, and maybe bump up the arrow weight.